Flow valve devices



Dec. 4, 1962 w. A. DUDLEY 2 2 FLOW VALVE DEVICES Original Filed May 20,1957 2 Sheets-Sheet l WW /fl 20 5 g 5 1% L i /4 ix l L- y I l 29 y 25 Z.30 -22 20a J4 37 36a E /4- 4 354 \W 43 /7\ /o l it 1 36 206 L5 32 3/ I.Q 206 J3 /9 Q i I /j Q/Q J}: w I v 49 W////am A. Dad/9y 404 .79 IN VENTOR.

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United States Patent Ofifice Re. 25,292 'Reissued Dec. 4, 1962 25,292FLOW VALVE DEVICES William A. Dudley, Dallas, Tex., assignor to MerlaTool Corporation, Dallas, Ten, a corporation of Texas Original No.2,994,335, dated Aug. 1, 1961, Ser. No. 66%,147, May 20, 1957.Application for reissue Sept. 25, 1961, Ser. No. 141,568

4 Claims. ((11. 137-455) Matter enclosed in heavy brackets 1 appears inthe original patent but forms no part of this reissue specification;matter printed in italics indicates the additions made by reissue.

This invention relates to new and useful improvements in flow valvedevices.

One object of the invention is to provide an improved flow valve devicefor controlling the admission of a lifting fluid or gas into a welltubing or conductor, said device being of the intermitter type and beingconstructed so as to lend itself to wire line operation, whereby thedevice may be positioned within and removed from the well tubing bymeans of a wire line.

An important object of the invention is to provide an improved flowvalve device having a main valve for controlling the admission oflifting fluid into a well conductor, together with an actuating pistonfor controlling movement of said valve; the device including means forbalancing and unbalancing the forces acting upon the actuating piston sothat the lifting gas pressure, which is acting upon the piston, may movesaid piston to open and close said valve in accordance with forceconditions across said piston.

Another object is to provide a flow valve device having a main valvewhich is positively moved to open position by the pressure of thelifting gas and which is positively moved to closed position also bysaid lifting gas, whereby ample power to affect movement of the valve isassured.

Still another object is to provide a flow valve device, of the characterdescribed, wherein the balancing or unbalancing of forces across theactuating piston is controlled by a pilot valve, which valve is operatedsolely in accordance with the pressure of the lifting gas, whereby saidlifting gas must be of a predetermined pressure in order to open saidpilot valve and must fall to a predetermined pressure before the pilotvalve closes; the opening and closing of the pilot valve controlling theoperation of the main valve through said balancing and unbalancing offorces across the actuating piston.

A further object is to provide a valve device, of the characterdescribed, wherein the main valve and the pilot valve are actuated bypressure from a common source and also wherein the pressure, whichactuates both valves, is discharged into a common area; the arrangementpermitting a simplified, compact unit which lends itself to wire lineoperation.

Still another object is to provide a flow device wherein the main valvehas direct connection with an actuating piston, with the areas of thepiston and main valve being so arranged that the pressure of the liftinggas, the admission of which gas is controlled by a pilot valve,functions to open and close said main valve.

The construction designed to carry out the invention will be hereinafterdescribed, together with other features thereof.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown,and wherein:

FIGURE 1 is a view partly in section and partly in elevation andillustrating a flow valve device, constructed in accordance with theinvention, mounted in a Well tubing or well conductor.

FIGURE 2 is an enlarged vertical sectional view of the flow valvedevice, with the upper end of the device not shown.

FIGURE 3 is a horizontal cross-sectional view, taken on the line 33 ofFIGURE 2,

FIGURE 4 is a horizontal cross-sectional view, taken on the line 4-4 ofFIGURE 2,

FIGURE 5 is a schematic view showing the main valve in a closedposition, and

FIGURE 6 is a view similar to FIGURE 5 illustrating the valve in an openposition.

In the drawings the numeral 10 designates a well tubing or conductorwhich extends downwardly through a well casing 11 disposed within a wellbore W. As illustrated, the tubing it) is formed with a chamber orpocket 12 at one side therein for receiving the flow valve device whichis generally indicated by the letter V. The device V is formed with theusual fishing neck 13 at its upper end, whereby a wire line may beconnected to the device to lower the same into position or to remove thedevice from the tubing. The device is provided with an upper packingelement 14 and a lower packing element 15, which are adapted to sealwith the bore 16 of the pocket 12. A fluid inlet opening 17 is providedin the gas, which is present within the casing 11, into the spacebetween the packing elements 14 and 15. As will be ex? plained, thislifting gas is controlled in its admission to the well tubing by thedevice V. The lower end of the flow valve device has openings 13 throughwhich the lifting gas may pass into the lower portion of the pocket oroffset and from this point said gas may enter the tubing string througha port 19. Upon entering the well tubing or conductor, the lifting gaswill, of course, lift the well fluids, which may be present therein,upwardly to the surface in the usual well known manner.

The valve device V includes an outer housing 20, which is formed ofseveral sections which are threaded or otherwise secured to each other.Within the upper portion of the housing is a pilot valve assembly whichincludes a bellows 21 having its upper end suitably secured within thehousing and having its lower end connected to a pilot valve stem 22. Acoil spring 23 surrounds the valve stem and exerts its pressure toconstantly urge the valve stem in a downward direction which would tendto maintain the bellows 21 in its expanded position. The lower end ofthe stem 22 carries a pilot valve 24 and such valve is adapted to engagean annular seat 25. The spring 23 has a predetermined pressure and, aswill be explained, lifting gas pressure is in troduced into the upperend of the casing or housing 20 and acts upon the bellows 21 to collapsethe same, overcoming the tension of spring 23 to unseat the pilot valve.Whenever the pressure within the upper portion of the housing is lessthan the force exerted by the spring 23, the pilot valve is seated. Asshown in FIGURE 2, the pilot valve 24 and its seat 25 are substantiallyopposite the upper packing element 14, which is mounted on the exteriorof the device and which seals with the bore of the pocket or oifsetportion 12.

Below the pilot valve 24 is an intermediate housing section 2021, aninlet thimble section 20b and a lower section 20c. Within the section20a, an annular cylinder bore of the cylinder.

tubular main valve stem 30, which extends downwardly through theintermediate section 29a and section 20b of the housing. The lower endof the valve stem carries a main valve 31, which is upwardly seatingagainst an annular seat 32 formed within the lower end of the housingsection 20b. The valve stem 39 is formedwith an axial restricted bore 33which extends entirely through the stem.

A coil spring 34 surrounds the valve stem and has its upper end engagingthe piston 28 with its lower end supported upon a retaining washer 35which rests upon an internal shoulder 36 provided within the upperportion of the section 29b. The spring 34- constantly exerts itspressure to urge the piston 28 upwardly within its cylinder 26 and sincethe main valve 31 is secured to the lower end of the valve stem, thisspring also acts to urge the main valve to a seated position in themanner shown in FIGURE 2. Upward movement of the piston 28 is, ofcourse, limited by the main valve 31 engaging its seat, while downwardmovement of the piston is restricted by a resilient bumper assembly 36a.This assembly comprises a plurality of elastic packing rings which aremounted on an annular retainer sleeve 37.

The lower packing element 15 is suitably mounted on the exterior of thelower housing section 200. The openings 18, which conduct fluid to theinterior of section 20c, are provided in the lower end of said sectionand an upwardly seating check valve 38 is mounted within the borethereof. The check valve 38 includes a valve member 39 having an O-ringseal thereon arranged to seal with the bore 40 of the lower portion ofthe section 26c to prevent a back-flow through the device; A stopshoulder 40a is engageable by an external annular projection 40b on thevalve member to limit upward movement of said member. A light coilspring 41 supports the check valve in a predetermined open positionrelative to bore 40, whereby the valve is made more sensitive to backflow.

The lifting gas or fluid, which is to be introduced into the well tubingor conductor 10, is normally present in the annular space S between thetubing and the well casing 11. This lifting gas is introduced into theannular space at the upper end thereof and its pressure is usuallycontrolled from the surface. The lifting gas pressure may enter theupper end of the housing 20 so as to act upon the bellows 21 throughinlet ports 42 which are formed in the intermediate section 20a of thehousing just below the packing element 14. This pressure, after passingthrough the ports 42, passes around the valve seat 25, then upwardlypast the pilot valve 24 and into the interior of the housing in the areasurrounding the spring 23 and bellows 21. The lifting gas may also enterthe interior of the intermediate section 20a below the piston 28 througha plurality of radial ports 43 which are provided at the lower end ofthe section 203, (FIGURE 2). It will be noted that the ports 43 arelocated above the lower packing element 15. Thus, the lifting gaspressure entering ports or openings 17 in the pocket or ofiset portion12, enters the space between the packing elements 14 and and may thenflow through the ports 42 to act on the bellows in the manner described,and may also flow through the ports 43 to act on the under side of thepiston 28. Also, this pressure may act upon the upper surface of themain valve 31.

The tubing pressure, that is, the pressure, which is present within thewell tubing or conductor 10 may enter the openings 18 in the lower endof the section c and will act against the under side of the main valve31. Be cause the valve stem has a bore 33 extending entirelytherethrough, this tubing pressure may also flow upwardly and act uponthe upper surface of the piston 28. Thus, with the parts in the positionshown in FIGURE 2, casing pressure will be present within the upperportion of the housing acting-on the bellows 21 and will be present inthe sections 20a and 20b of the housing acting on the lower end of thepiston 28 and the upper surface of the main valve. Tubing pressure maybe acting on the lower end of the valve 31 and also upon the upper endof the piston 28 through the bore 33.

In the operation of the device, reference is made to FIGURES 5 and 6which schematically illustrate the piston and main valve and show itsrelationship to the pilot valve 24. The etfective area of the uppersurface of the piston 28 as indicated at A in FIGURE 5, while theeffective area of the under side of the piston is indicated at B. Thearea on the upper end of the main valve 31, which is acted upon by thecasing pressure within the sections 20a and 26b of the housing, isdesignated C in FIGURE 5, while the lower effective area of said valveis indicated at D. As explained, the casing pressure is present withinthe interior of the housing sections Zila and Ztlb and is, therefore,acting upwardly against the area B of the under side of the piston andis acting downwardly on the upper surface or effective area C of themain valve 31. Since the area B is greater than the area C, the effectof this pressure would be to urge the piston in an upward direction.This action is assisted by the force of the spring 34 which is alsoacting upwardly on the piston.

Casing pressure is also entering through ports 42 upwardly around thepilot valve 24 and against the exterior of the pilot bellows 21. Withthe check valve 33 in the lower end of the device (not shown in FIGURE5) in its lower or open position, the tubing pressure is acting againstthe effective area D of the main valve 31 and upwardly through thecentral bore 33 of the valve stem and against the upper effective area Aof the piston 28. The area A is a larger effective area than the area Dand thus the eifect of the tubing pressure is to urge the piston in adownward direction which would be toward a position unseating the mainvalve. However, in normal operation, thecasing pressure and spring aresufiicient to hold the main valve closed.

In describing the operation of the valve, it will be assumed that thevalve 31 will close when there is 500 p.s.i. pressure in the casing orannulus S and that the valve will open when this pressure is built up to550 p.s.i. With the valve in closed position as shown in FIGURE 5, thecasing pressure is built up to 550 p.s.i. When this occurs, the force ofthe pilot spring 23, which is holding the pilot valve 24 seated, isovercome and the pilot is moved off of its seat 25. Unseating of thepilot valve 24 permits the 550 p.s.i. casing pressure to pass downwardlythrough the bore 25a of the pilot valve seat and into the area above thepiston 28, this pressure acting upon the area A. As explained, the samecasing pressure was present in the interior of the sections 20a and 20bacting upwardly against area B of the piston and downwardly on area C ofthe main valve. As the pressure above the piston acting on area Abalances the force which is acting on area B on the lower side of thepiston, the full casing pressure acting upon the effective area C of themain valve 31 moves said main valve downwardly to an unseated positionas shown in FIGURE 6.

When this occurs, the casing pressure may flow past the valve 31,outwardly through the lower discharge ports 18 of the device and thenthrough the opening 19 into the well tubing to lift the well fluidstherein. As the pressure flows into the well tubing, there is areduction in the casing pressure and as this pressure falls to 500p.s.i., the spring 23 acting on the pilot valve 24 moves the pilot valveto its seated position thereby closing off communication between thesource of the casing pressure and the upper end of the piston 28.Thereafter, the pressure, which has been acting on the area A, ispermitted to escape through the restricted bore 33 of the main valvestem and to pass outwardly with the lifting gas and into the welltubing. The escape of pressure from above the piston A reduces thepressure acting on area A and when the force of this pressure is lessthan the force of the pressure within the section 20a acting on thelower end of the piston, the piston is moved upwardly to again seat themain valve. The parts will then remain in this position until the casingpressure is again built up in order to unseat the pilot valve in themanner heretofore described.

From the foregoing, it is obvious that the casing pressure is introducedinto the intermediate and thimble sections 20a and 20b of the housingand is at all times act ing upwardly upon the piston 28 and downwardlyupon the area C of the main valve 31. By opening and closing the pilotvalve 24, a balance or unbalance of forces acting upon the piston 28 iseffected and it is this balance or unbalance which results in movementof the main valve. In the case where the pilot valve is open andpressure is admitted to the area above the piston 28, the reaching of abalanced condition causes the casing pressure acting on the area C ofthe main valve to move said valve open. When the pilot valve is closedand pressure is permitted to bleed oft" from the area above the piston,the forces across the piston are again unbalanced and the casingpressure within the intermediate section Ztla of the housing actsagainst the under side of the piston or the area B to move the pistonupwardly. This is permitted because the area B or the piston is largerthan the effective area C of the main valve which would resist theclosing movement. The opening an closing of the main valve isaccomplished solely by the casing pressure which acts upon the difierentcross-sectional area.

It is pointed out that the supply of pressure, which operates thebellows, is the same as that which is introduced into the sections 26aand 20b to effect operation of the main valve. This same pressure is thelifting gas which is ultimately introduced into the well tubing. It isnoted that the gas, which actuates the pilot valve and which enters thearea above the piston 28, is finally discharged through the bore 33 ofthe valve stem and is also directed to the well tubing. The device isrelatively simple in construction and is extremely compact so that itmay be made of a sulficiently small diameter to lend itself to wire lineoperation. Although the device has been shown as lowered into andremoved from the tubing string on a wire line by locating said device inan otfset portion or pocket 12, the invention is not to be limited to awire line valve for obviously the valve would function just asefficiently if it were mounted in an offset portion in the tubing stringas a part of the string. The particular construction of the piston 28and the valve 31 are, of course, subject to variation although thepresent construction makes it possible to use a single seal ring toefiect the proper sealing action. The packing elements 14 and on theexterior of the housing have been shown as chevron type packing butobviously any suitable means may be provided.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in the size,shape and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimswithout departing from the spirit of the invention.

What I claim is:

1. A gas lift valve comprising, a tubular housing having an outlet atone end, main gas and pilot gas inlets in an intermediate section ofsaid housing and spaced from said outlet, seal means on the housing andspaced from the main and pilot gas inlets toward the other end of thehousing, seal means on the housing between said outlet and inlets, aflow passageway in the housing connecting the main gas inlet and theoutlet, a valve seat in said passageway, a main valve member cooperablcwith the valve seat to control flow through the passageway, a pressureresponsive member in the housingspaced from the main gas inlet towardthe other end of the housing and connected to said main valve member,means establishing fluid communication between one side of the pressureresponsive member and the main gas inlet, means including a bleedpassageway establishing communication between the other side of thepressure responsive member and said outlet, means including a pilotvalve seat spaced from the pressure responsive member toward the otherend of the housing establishing communication between said other side ofthe pressure responsive member and the pilot gas inlet, a pilot valvemember cooperable with said pilot valve seat controlling flow of pilotgas to the other side of the pressure responsive member, bellows meansspaced from said pressure responsive member and pilot valve seat towardsaid other end of the housing and connected to said pilot valve member,and means conducting fluid from said pilot gas inlet to said bellows tooperate said bellows means in response to change in pressure at saidpilot gas inlet, said pilot valve and bellows so arranged that upon anincrease in pilot pressure to a selected value the pilot valve membermoves to open position, said main valve member and pressure responsivemember so arranged that when the pilot valve member is in seatedposition the main valve member is in seated position and when the pilotvalve member is in non-seated position the main valve member is innon-seated position.

2. A gas lift valve comprising, a tubular housing having an outlet atits lower end, main gas and pilot gas inlets spaced upwardly from saidoutlet, seal means on the housing above the main and pilot gas inlets,seal means on the housing above the outlet and below the main and pilotgas inlet-s, a flow passageway in the housing connecting the main gasinlet and the outlet, a valve seat in said passageway, a main valvemember cooperable with the valve seat to control flow through thepassageway, a cylinder in the housing above the main gas inlet, a pistonsealingly engaging said cylinder and connected to said valve member,means establishing fluid comunication between one side of the piston andthe main gas inlet, means including a bleed passageway establishingcommunication between the other side of the piston and said outlet,means including a pilot valve seat above the cylinder establishingcommunication between said other side of the piston and the pilot gasinlet, a pilot valve member cooperable with said pilot valve seatcontrolling flow of pilot gas to said other side of the piston, bellowsmeans above said cylinder and pilot valve seat and connected to saidpilot valve, and means conducting fluid from said pilot gas inlet tosaid bellows to operate said bellows means in response to change inpressure at said pilot gas inlet, said pilot valve and bellows soarranged that upon an increase in pilot pressure to a selected value thepilot valve member moves to open position, said main valve member andpiston so arranged that when the pilot valve member is in seatedposition the main valve member is in seated position and when the pilotvalve member is in non-seated position the main valve member is innon-seated position.

3. A gas lift valve comprisng, a tubular housing, spaced seal means onthe exterior of the housing defining therebetween an intermediatesection of the housing, main and pilot gas passageways through the bodybeginning in so id intermediate section and ending outside saidintermediate section, a valve seat in said main gas passageway, a mainvalve member cooperable with the valve seat to control flow through thepassageway, a pressure responsive member connected to said main valvemember and positioned endwise of the housing from said valve seat, meansestablishing fluid communication between one side of the pressureresponsive member and the exterior of the housing at said intermediatesection, the other side of said pressure responsive member providing aportion of said pilot gas passageway whereby said other side of thepressure rcsponsive member is exposed to pilot gas, a pilot valve seatacross said pilot gas passageway between the pressure responsive memberand the beginning of said pilot gas passageway, said pilot valve seatarranged on theside of the pressure responsivemember opposite the mainvalve seat, pilot valve means controlling flow through the pilot valveseat, said pilot gas passageway including a bleed section restrictingflow therethrough to provide a pressure drop at the bleed section whenthe pilot valve member is in open position, and bellows means on theside of the pilot valve member remote from said pressure responsivemember and exposed to fluid in said pilot gas passageway, said bellowsoperably associated with and controlling operation of the pilot valvemember, said pilot valve and bellows so arranged that upon an increasein pilot pressure to a selected value the pilot valvemember moves toopen position, said main valve member and pressure responsive member soarranged that when the pilot valve member is in seated position the mainvalve member is in seated position, and when the pilot valve member isin non-seated position the main valve member is in non-seated position.

4. A gas lift valve comprising, a tubular housing having an outlet atone end, main gas and pilot gas inlets spaced from said outlet, sealmeans on the housing between the outlet and said inlets, seal means onthe housing between the other end of the housing and said inlets, a flowpassageway in the housing connecting the main gas inlet and the outlet,a valve seat in said passageway, a main valve member cooperable with thevalve seat to control flow through the passageway, a cylinder in thehousing on said other end side of the valve seat, a piston sealinglyengaging said cylinder and connected to said main valve member, meansestablishing fluid communication between one side of the piston and themain gas inlet, a pilot gas passageway extending from the pilot gasinlet to said cylinder on the other side of the piston and to an outletin the body outside of the area defined by said two seal means, a pilotvalve seat across said pilot gas passageway between said cylinder andthe other end of the housing, a pilot valve member controlling flowthrough the pilot valve seat, said pilot gas passageway including ableed section restricting flow therethrough to provide a pressure dropat the bleed section when the pilot valve member is in open position,and bellows means on the side of the pilot valve member remote from saidcylinder and exposed to fluid in said conduit, said bellows operablyassociated with and controlling operation of the pilot valve member,said pilot valve and bellows so arranged that upon an increase in pilotpressure to a selected value the pilot valve member moves to openposition, said means valve member and pressure responsive member soarranged that when the pilot valve member is in seated position the mainvalve member is in seated position, and when the pilot valve member isin non-seated position the main valve member is in non-seated position.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS 1,724,855 Small Aug. 13, 1929 2,446,680 WaltonAug. 10, 1948 2,487,418 Birkemeier Nov. 8, 1949 2,573,110 Robison Oct.30, 1951 2,744,538 Stevenson May 8, 1956

